Control mechanism for model airplanes



Dec. 28,- "1948. J. K. SHANNON 2,457,281

' CONTROL MECHANISM FOR MODEL AIRPLANES Filed May 11, 1946 v 2Sheets-Sheebl INVENTOR JOHN KSHANNON N AT ORNEYS BEE, 2%, 1948. J, K. NQ2,457,281

CONTROL MECHANISM FOR MODEL AIRPLANES Filed May 11,.1946 v 2Sheets-Sheet 2 INVENTOR JOHN KSHANNON ATTORNEYS Patented Dec. 28, 1948MECHANISM FOR 'MGDEL AIRPLANE? CONTROL its John K. Shannon, Kenosha,Wis.

Application May 11, 1946, -Serial No. 669 021 2 was. (01. ,4678)invention appertains to model or toy vehicles and more particularly to apowered model.

airplane.

One of the primary objects 'of my invention is to provide means forautomatically controlling the maneuvers of powered model-airplanes,especially in free flight, or any steerable contrivance;

Another salient object of the invention is to provide means whereby adevice, through the use of a novel mechanism,'can be causedto followautomatically a predetermined patternof maneu-' vers.

A further object of this invention is to provide a, rotatable spiral camtrack operated from a spring or other motor having a spring pressedlever engaging the same and operatively connected to the control surfaceof the airplanepr other device the peripheral contour of the cam trackcausing the lever to actuate against the ten sion of its spring andbring about the movement of the control surface and thus causingtheairplane to follow a predetermined maneuver or maneuvers. A furtherimportant object of my invention is to provide a spiral cam track madeup of one-or more sections of apredetermined peripheral'cone figuration,the sections being detachablyassociated together on a common driveshaft, so that cam track sections of different configurations canbereadily substituted for other sections on the shaft and therebybringabout any desired selected pattern of controlled movement.

A still. further object of my invention. is to ,pro vide a novel andsimple device for controlling the movements of a powered model-airplaneand the like, which will be durable and efficient in use and one thatcan be incorporated with a model airplane at a small cost.

With these and other objects in View, the invention consists in thenovel construction, arrangement. and formation of parts, as willbehereinafter more specifically described, claimed, and illustrated inthe accompanying drawings, in

which drawings: I Fig. 1 is a fragmentary perspective view of a poweredmodel airplane having my novel control mechanism incorporated therewith,parts of the figure being shown broken away and in section to illustratestructural detail.

Fig. 2 is a longitudinal fragmentary sectional view through the bodyorfuselage of theairplane, illustrating my novel cam mechanism and one of:the operating .levers. I r Fig. 3 is a fragmentary transverse sectionalview taken substantially 0n: the line -3-3 of Figs I 2 g 2. looking inthe direction of the arrows, illustrating the novel cam and themounting. and drive motor therefor.

Fig. 4 is an edge elevational view of oneofthe cam tracksections; and

5 is an enlarged fragmentary detail. secs tional'view taken on the line55 of Fig. 3 looking in the direction of the arrows, illustrating themeans of detachably mounting the cam tracksec-a tions on the squaredrive shaft. Y

Referring to the drawings in detail, wherein similar referencecharacters designate corre-- spending parts throughout the severa1views, the letter A generally indicates a model airplane which can bepowered by a miniature internal combustion engine 6. The method ofpowering the airplane forms no part of my present'invention and, hence,will not be described in detail. The airplane itself can be of themodeltype now found in the open market and it is to be noted that the sameincludes the fuselage orbodyfl; wings 8, and landing gear 9. Thewings 8are provided with pivoted ailerons ID. The tail of the planecarries thevertical rudder II, which is pivoted forswinging movement, and theelevators lz. These elevators are also mountedon a horizontal pivot forswinging movement. The control surfaces [0, H, and I2 are operatedthrough my novel mechanism l3, which will now be described."

This mechanism l3 includes a spiral cam track It preferably madeup of aplurality of cam track sections l5. These cam track sections have theirperiphery provided with a predetermined contour and the same is providedwith cam lobes I6 and valleys ll. The exact pattern of these lobes andvalleys can be made to suit varying conditions and the surface to becontrolled and the sections are made to interfit so that acontinuousfcam track will be providedwhen the same are associ atedtogether. The axialcenters of the cam track sections are provided withsquare-or polygonal shaped'o'pen'ings it? so that the same can bedetachably mounted upon a square or polygonal shaped shaft l9.

The shaft i9 is externally threaded at its corners, as area, and isrotatablymounted in a'supporting bracket 21. Hence, when the shaftisrotated, the cam track will be turned therewith.

The bracket 2| includes a base plate 22' and an upstanding rigidsupporting arm 23 through whicht-he shaft rotatably extends. Anadjustableend ofthe shaft remote from the end supported by the rigidarm23, and this arm 24 is likewise provided with an opening for rotatablyreceiving the shaft. The lower end of the arm 24 is of a hooked shape,as indicated by the reference character 25, and this hooked end isadapted to be inserted in a selected slot 26 formed in the base plate22. It is to be noted that there is a plurality of these slots 26extending along the length of the base plate, 7 I

The shaft [9 is adapted to be operated from a suitable motor and Ipreferably provide a spring motor 21 for this purpose, The motor can beof the type generally employed for driving mechanical toys and thespring can be wound by.

.4 in turn, operatively connected to the upper end of the short arm 32of the lever 29.

The rudder H has secured thereto an outwardly projecting rudder arm 44and this rudder arm has pivotally and operatively connected thereto aforwardly extending link or rod 45, which is pivotally and operativelyconnected to the short arm of the lever 38. The elevators 12 each haveconnected thereto a depending elevator operating arm or crank 46.Pivotally and operatively connected to each arm 46 is an operating rodor link 41. The forward ends of the links 4'! are pivotally andoperatively connected to the suitable key (not shown). The windingshaft'for the spring motor is indicated by the reference character 28.The shaft 49 is driven from the spring motor and the bracket 21 can beconnected to the casing of the spring motor so that the motor and camtrack can be handled as a unit, if such should be desired. The springmotor 21,

the cam I4 and the bracket 2! are all rigidly secured in the body 1 atthe desired point, for balance and the like. The spring motor itself canbe'wound and set in motionby a trip lever (not shown), and the lever canbe tripped either manually or by a timing mechanism (not shown).

I'n' orderto operate the control surfaces- Ill, II, and I2, from the camtrack, I employ a plurality of levers29f30, and 3!. The lever 29 isemployed for operating the ailerons). The lever 30 is employedfor-operating the rudder H and the lever 3| i's 'eniployed for operatingthe elevators I2. All ofthese levers are of the bell crank type and,hence, include angularly related short arms 32 and long arms 33, Allofthe levers are rockably mounted at their angles by elongated grooves ona pivot pinv 34 and this pivot pin can be carried by a bracket35 securedinside of the fuselage in rear of'the cam track. The bracket 35 isprovided with upstanding guide arms 38 for the levers and the levers arelocated between these guide arms.

Y Attention is called to the mounting of these levers and it is to benoted that the mounting is such that the levers can rock on the pivotpin 34 andalso have a limited swinging movement in a horizontal planefor a purpose which will later p ar.

[The-forward ends of the long arms 33 of the levers each carries arotatable grooved roller 31 and these rollers rideon the periphery ofthe spiral cam track I4. A contractile coil spring 38 is providedforeach lever. and the coil springs function to hold the long arms ofthelevers down with the rollers 31 in contact with the cam. Hence, therollers will follow the undulations in the cam track and the levers willrise and fall according to the shape of the cam track. Obviously therollers will follow the spiralcam track during the rotation thereof andthe cam track can carry a stop arm 39 so that when one roller reachesthe end of the cam track, further rotation of the cam track will bestopped. This will prevent the riding of the rollers ofiof the-camtrack.

.In order to bring about the movement of the ailerons l 0, I mount inthe wings 8 rock shafts 40.

The outer ends of the rock shafts carry radially extending operatingarms 4! which are anchored in their respective aileron. Hence, when therock shaftsare turned; the ailerons will be moved up ordown according tothe direction of rotation of the rock shafts. The inner ends of the rockshafts carry cranks 42 a'nd ea'ch crank has operatively connectedthereto a link 43 and these links are,

shaft l9 and the levers are swung over on the cam tracks to theirinitial starting position and so that the rollers carried thereby canfollow along the spiral cam track a certain desired distance and untilthe stop arm 38 is reached. Obviously, the undulations in the cam trackwill move the levers up and down and this movement will be transmittedto the control surfaces ill, II, and I2 by the operating rods or links43, 45, and 47.

In actual practice, the cam track sections have portions which representneutral or normal positions for the ailerons, rudder and elevators. andthe tips and lobes are such as to cause these control surfaces to moveup and down or to the right or left, as the case may be. After thedesired cam track has been inserted and the levers initially adjusted orset thereon, the airplane is ready for flight in the ordinary method nowursued in handling toy or model airplanes.

It is to be also understood that the cam track sections are coordinatedso that the control sur faces will move at the proper time, directionand distance taking into consideration the flight characteristics of themodel being used. The pattern of travel by the model will be madewithout any attention on the part of the operator, as the spiral camtrack rotates as the model travels on its course.

-While I have specifically shown by attachment l3 applied to a motorpowered airplane, it is to be understood that the principles of myinvention can be used for steering boats, other toy vehicles, orappliances.

Changes in details may be made without departing from the spirit or thescope of my invention, but what I claim as new is:

1. In a toy vehicle having a pivoted control surface, a spiral cam trackprovided on its periphery with lobes and valleys, means for rotatingsaid cam track, a pivoted spring pressed lever engaging said cam trackand movable therealong during the rotation thereof, said lever beingadapted to rise and fall different distances during its travel on saidcam track by said lobes and valleys, and means operatively connectingthe lever to the pivoted control surface for swinging the same, said camtrack including a plurality of de tachable cam track sections ofdifferent peripheral configurations.

2. In a toy vehicle having at least one pivoted control surface, aspiral cam track including a plurality of detachable andinterconnectedsections, a rotatable common shaft for said sections for turning thesame, means for rotating the shaft, a bell crank lever rockably mountedat its angle, a grooved roller on said bell crank receiving and engagingthe cam track, means normally holding the roller in engagement with thecam track. and means operatively connecting the lever to the controlsurface for swinging said control surface during rocking movement of thelever under influence of the cam.

JOHN K. SHANNON.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number Number UNITED STATES PATENTS (Addition to No. 401,918)

